Separable attachment-plug.



RQB.BENJAMIN.

. SBPARABLE ATTACHMENT PLUG.

APPLICATION FILED NOV.21, 1908. 190229815, I A Patented Ap1.9,1912.

2 SHEETS-SHEET I.

i fm MW@ R. B. BENJAMIN.

SEPARABLE ATTACHMENT PLUG.

APPLICATION FILED Nov. 21. 190s.

Patented Apr. 9,1912.

2 SHEETS*SHEET 2.

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UMTED STATE-s PATENT onirica.,

BEUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS, ASSIGNOR TO BENJAMINIslIElCJIRIC MAN UFA'CTURINGCOMPAN Y, 0F CHICAGO, ILLINOIS, ACORPORATION 0F ILLINOIS.

SEPARABLE ATTACHMENT-PLUG. y

ASipecifcation of Letters Patent.

Patented Apr. 9, 1912.

To all whom it may concern:

Be it known that I, REUBEN B. BENJA- MIN, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have inventednew and useful Improvements in Separable"Attachment-Plugs, ofwhich the following' .is a full, clear, concise, and exactdescription, reference being had to the accompanying drawing, forming apart of this specification. i

My invention relates to attachment plugs; and its object is theprovision of a simple and eiicient device by the kuse' of which the`feed conductors leading to movable electrical devices, such asV fanmotors, table lamps, etc., can be readily brought into connection withthe terminals of a socket or similar fixture disposed in an electriccircuit.

Attachment plugs of ordinary construction are subject to thedisadvantage that in connecting them to any of the kinds of sockets ingeneral use, it is very .diiicult to avoid twisting' and consequentkinking of the conductors and, furthermore,'consider able time has to bespent in making the connection. This waste of time becomes of greatimportance when the connection has to be very .frequently made andbroken, as would be the case, for instance, in the use of, electricallyheated fiat-irons and similar household implements.

In an attachment plug constructed in accordance with `the inventionforming the subject of this specification, the outer corrugated orthreaded contact member is ar ranged to be readil separated from thebody of the plug. lilith such a devlce the corrugated contact member maybe first 1n# vserted into a socket so as to make connection with one ofthe contacts thereof, and the plug body kmay be then 'connected withthis Contact member or disconnected therefrom'as occasion. requires.When the plug body is connected with -the corrugated contact member anend contact carried by said plug body engages one of the contacts of thesocket, and, at the same time, suitable coengaging means on thecorrugated contact member and the plug body make electrical connection`witheach other and thus place the corrugated contact member invcommunication with a 'binding terminal' car- Avational view of the riedby the plug body, the vother binding terminal being always connectedwith the end contact. By this means I obtain a plugof simple andeconomical construction which has a neat appearance and is eiicient andconvenient in use.

In the. accompanying drawings I .have shown two embodiments of myinvention, Figures l to 6 inclusive illustrating one. ef theembodiments, while Figs. 7 to 14 inelusive illustrate the otherembodiment. Fig. lV is an elevationalcview of the irst form of plug,showing thek removable corrugated contact in place on the plug body;Fig. 2 is a view similar to Fig. 1 showing the removable contact memberseparated from the plug body; 3 is an elevational view of the plug bodyseparated from the removable contact member, and-turned to present theside opposite that seen in. Fig. 2; Fig.' 4 is an end view of the plugbody separated from the removable contact member; Fig. 5 is a viewsimilar to Fig. l, but showing the plug in longitudinal section; Fig. 6is a fragmentary view illustrating a detail of the device upon anenlarged scale; Fig. is an elevational view of theother` form of thedevice, showing the removable contact member in place on the plug body;Fig. 8 is a view similar to Fig. 7 but showing the removable contactmember separated from the plug body; Fig. 9 is an eley plug bodyseparatedr from the removable contact member and turned' to present theside opposite to that seen in Fig. 8: Fig. 10 is a planview of thedevice. partly sectional, on |the lineV 10-10 of Fig. 7 Fig. 11 is anend view of the plug body separated from the removable Vcontact;\Fig. 12shows a partial longitudinal section taken on the line12-12 of Fig. 7looking in the direction indicated by the arrows; Fig. 13 shows alongitudinal section as on the line'13-13 of Fig. 11; and Fig. 14 is aninverted plan of the removable contact member. U Like referencecharacters refer to like partsthroughout the specification and dran'-mgs a The attachment plug, in both forms of the device, consists of aplug body and a removable outer part 16, which latter will preferablyhave the form of a tubular shell,

through the end of4 which the end contact on the plug body extends whenthe parts are.

. placed together. Throughout the4 follow- Yio mg specification, theplug body will be ie'v ferred to as the body and the removable contactmember as the shell Referring rst to Figs. 1 to 6 inclusive, the shell,in this form of the device, consists of a corrugated or screw threadedconducting member 17, whichl may be similar in character to theouter-,contact member on plugs of ordinary construction, and is formedwith an inwardly extending end .iange 18.- ,Disposed within the upperpart` of the corrugated contact member 17, and extending beyond the endthereof, is aninsul'ating block 19, formed with a central aperturethrough which the end Contact of thefbody 15 is adapted\to pass. Theblock 19 is formed with' an outwardly extending flan e 20bearing againstthe flange 18. An

of the rivets 22 are conductor strips 23 which extend downwardly within.the Sleeve 21. The conductor strips 23, which are preferably two innumber, are bent over` at their ends to form inwardly extending tongues24, adapted to coperate'with spring members upon the body 15, as will behereinafter described..

The body 15 comprises an insulating base 25 carrying the terminals whichreceive the ends of the leading-out wires. Secured to the base 25 is ametallic collar 2 6 which is screw threaded 'at its' lower end toreceive a thumb piece 27which is formed with a screw threaded neck 27entering the screw threaded portion of the'collar 26. The collar 26 ispreferably secured to the base 25 by bending its top edge over -oneormore projections formed' on the base.

. Secured to the collar 26 adjacent the u per edge thereof, andextending rearwarv y along theexterior of the collar, are a pair ofmetallic spring strips 28. The `spring strips 28 are bent outwardly attheir rear.-

ward ends and to the outwardly bent por` tions are aixed insulatingknobs 28, The springs 28 are also formed with apertures 29 for receivingthe tongues 24 on the conductor strips 23 when the plug body is insertedin the shell. The contact springs 28 tend. to spring a art slightly andaway romjthe plu bo y, but may e forced in toward the colar 26 bypressure of the fin# gers upon the knobs 28". -When the body is inserted'into the shell the spring strips 28 are forced to move inward u ntilthe tongues 24 reach, and enter, the openings 29, whereupon thesestripsare enabled to spring outward to a slight extent, the body being thenVlocked within the shell and not releasable until the knobs 28a` arepressed to disengage the tongues 24 from the openings 29, when.

the body maybe removed. Recesses 21 may be formed, if desired, inthesleeve 21 of the shell for receiving the knobs 28; thus enabling thesleeve 21 to extend downward in close proximity with the thumb piece 27.

The sideof the base 25 4is formed with a recess 30 (See Fig. 3) forreceiving a plate 31 for a binding screw 32, which plate is secured tothe collar. 26. The recess 30 extendsv longitudinally of the base 254to, the lower end of the same and is of suicient width to receive thelead wire 33, the bared end of which is attached to the screw 32.

The base 25 is formed, near its upper end, with a flattened portion 34,to which is Secured, by means of a screw 35 passing through theupper-end of the base, a plate 36 which carries the end cont-act of thedevice, this plate carrying alsola binding screw 37. Extendinglongitudinally through the base 25, and opening below the plate 36, is apassage 38 through which extends lead wire 39, the bared end of which issecured inder the screw 37. The .plate 36 is formed with an extension 40extending beyond the end of theA b'ase and bent at right angles to lieflat thereupon. The extension 40 has an aperture formed therethrough insuch a position as to lie approximately over the axis of the insulatingbase. An axial well or recess41 is formed in the base immediately be-,low this opening. To. the extension 40 is se'cred a cup 42 having anaperture in its bottomregistering wit-h the aperture offthe v late.Telescoping'within the cup 42 is` an inverted cup 43 which forms the endcontact of the device, from the center of which a pin 44 extendsdownward through the aperturesof the cup 42 and `plate 40. lBetween thecups 42 and 43 is arranged a spiral spring .45 tending to separate thecups and force the inner cup forward beyond the end of the insulatingmember 19. The pin 44 is formed with an enlargement 46 on its inner end,vwhich enlargement engages with the .lower face of the plate 40 and thuslimits the forward travel of the cup 43. 4It will be seen that bypressing upon the upper end ofA the cup 43 it maybe made to telescopeinto the cup 42, the pin 44 entering the well 41.

In using y screwedinto the socket, the effect of whic may lbe said tobethat a second socket is formed, the terminals of which are theordinary centr contact ,of the socket, accessible through the opening ofthe insulating block 19, and the conductor strips 23, which are in thedevice the shell 16 is firmly electrical connection' .with the sleeve 17through the rivets 22.` `r1`he body 15 may be. said to now form a plug,of which the cup- 43 forms a compressible end contact and the contactspringsy28 form the other contact. The body l5 is pushed into the shell16 in such manner that the contact springs 28 engage the tongues 24 asabove described. When the body has been pushed in to a certain extent,the yielding end contact 43 into the shell 16,.the cup 43 telescopesinto 15 the 'cup 42, until the tongues 24 enter the openings 29.locking'the parts together. When it isdesired to remove the body fromthe shell 16, it is only necessary to press with the lingers upon theknobs 28* when .the body may be withdrawn.

Separable plugs as heretofore known -we`reusually constructed so that aprojection on one member engaged between spring clips onthe other, andconsiderable force was necessary to effect separation of the members.This-often resulted in damage to the plug itselfas well as to the socketand fixtures carried thereby. This disadvantage is obviated by myinvention since the plug 15 may be withdrawn from the shell 16 with theexpenditure o very little force,`

the spring 45 aiding in th separation of the members.

Referring to Figs. 7 to 14, the shell 16 in this case consists of acontact .sleeve 47 flanged inwardlyat its end to form a shoulf der 48and a neck 49. Upon the neck 49 is secured an insulating ring 50 havingan upwardly extending flange surrounding y the sleeve 47 fora portion ofits height, the sleeve 47 being flanged over beneath the ring 50 toretaip the latter in position. The ring 50 is formed with threeoutwardly extending recesses 51, the purpose of which will behereinafter described. An insulating lining sleeve 52 is arranged in themetallic sleeve 47 and extendsl from a point about midway between theends thereof to a short distance beyond the outer end of the metallicsleeve. .A part 53 of the insulating sleeve 52 is extended tothe bottomof the sleeve 47 for a purpose to be hereinafter described. The liningsleeve 52 issecured in y the conductor sleeve 47 by punching the latterinward to form projections 54 entering corresponding recesses formed bypunching in the side of the `lining sleeve 52. .The body 15 comprises aninsulating base 56 having laterally projecting lugs 57 formed thereon.Radially extendin arms 58, formed on a ring 59 upon which t e base isseated, areA bent up to extend along the lugs 57, and have their endsbent inward over the tops of these l toY secure the parts together. Thevbase is thus clamped between the ring 59 and the turned over ends of thearms 58.

The ring 59is formed with a lug 65 bent upward to lie in a recess 66formed in the insulating base 563 Thelug .65 carries a binding screw 67for holding the endof l aperture of sutiicient size to receive the two vleading-in wires. A screw threaded bushing 62 is screwed into the lowerend of the collar `60 and compresses betweenit and the disk 61, a ring63 of rubber or other flexible material, the aperture of which ring isnormally suilicient to allow the passage of the llead wirestherethrough. When the bushing 62 is screwed inward to compress theflexible ring 63, the Alatter is distorted, as .shown in Fig. 13, andcontracted so as to grip the conductors, whereby they are securelyclamped in position and any danger of damage being done to the terminalsot the plug by an accidental jerk upon the conductors is precluded. Aninsulating ring '64 is externallyscrewed upon the collar 60 to providemeans for holding the body when bleirlllg inserted in, orl withdrawnfrom, the s e The insulating base 56 is formed with a central chamber 68into which the lead wires can enter through the bushing 62 andcompressible ring 63. Leading from the recess 66 is an apertureconnecting it with the chamber 68, sothat the conductor to be securedunder the terminal 67 may be drawn therethrough. The insulating base isalso formed with a second recess. 69, communicating with the chamber 68,in which is arranged a platev 70 carrying the second binding terminal71. A depression 72 is formed in the outer end of the insulating baseand communicates, by means of a well 73, with the chamber 68. lThe upperehd of the plate 70 is bent over so as to form an ear 7 5, lying in thedepression 72. This ear is formed with ap aperture approximately coaxialwith the well 73. A metallic lining 74 is provided in the well 73, whichlining is reduced at its upper end to enter the aperture of the ear 75and flanged at its lower edge over the end of the well 73, thus securinthe plate 70 in position,

. Slida ly mounted in the aperture of the ear 75 is a plunger 76, formedat its upper end with a head 77 which constitutes the center or end.cont-act of4 the device, and is enlarged at'78 below the ear 75 to limitthe' forward movement-bf the plunger. Between `the head 77 and the, ear-75 of the plate 70 ris disposed a spiral compression spring 7 9.

The plunger 76 may be forced downward int-o the well 74 by pressure uponthe head 7 7 but when this pressure is removed, the plunger will bethrust out to its normal p0- sition by the action of the spring 79.

In using the plug, the shell 16 is rst screwed into the socket. The body15 is then inserted in such manner that the binding screw (3T and thearms 58 register with the recesses 51 of the ring 50. The body may bethen pushed in until the yielding contact 77 engages the center contactof the socket. The plug is then pushed farther in, the spring 79becoming compressed, until the shoulders 55, formed by the lower end ofthe arms 58, pass beyond the upper face of the shoulder lt8 ofthe shell.The body may then be rotated until the sides of the arms 58 strikeagainst the edge of the downward extension 53 of the insulating sleeve52, as shown in Fig. 10. When the plug has been rotated to thisvposition the terminal 71 will be located opposite the downwardextension 53, whereby any chance of sparking from the terminals 7l tot-he sleeve 47 is precluded. The body is now locked in position in theshell. One edge of the downward extension 53 is located at the side ofone of the openings 51, as will be clearly seen from Fig. 10, wherebythe turning of the body in the wrong direction is rendered impossible.ln this t'orm of my invention,

also, the exerciseof very litt-le force is necessary in order to effectthe separation of the body from the shell.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. An attachment plugmade in two separable parts, a corrugated contactmember carried by one of said parts, the-other of said parts beinginsertible thereinto from the rear, and an endcontact carried by saidinsertible part for engagement with the center contact of a socket.

2. A n attachment lug constructed in separable parts, one o said partsAbeing insertible into the other from the rear and carrying a yieldingcontact for engagement with t-he center contact of a socket, bindingterminals also carried by said insertible part, one of said bindingterminals being electrically connected to said yieldingcontact, theother of said separable parts including a corrugated contact member, and

means for making electrical connection between said corrugated contactmember and the other of said binding terminals when said separable partsare put together.

3. An attachment plugv made in separable parts, one of which isinsertible into the other from the'rear, an end contact carried by saidinsertible part for engagement with the center contact of a socket,binding terminals also carried by said insertible part,

a side contact member carried by the other of said separable parts, andmeans for connecting said side contact with one of said bindingterminals when said separable parts are put together.

4. An attachment plug made in separable parts, one of which isinsertible into the other from the rear and carries an end contact forengagement with the center contact of a socket, said part carrying alsobinding terminals, one of which is connected with said end contact, aside contact member carried by .the other of said separable parts, andmeans detachably locking said separable parts together and electricallyconnecting Said side Contact with another binding terminal-when saidseparable parts are put together.

5. An attachment plug made in two separable parts, one of which isinsertible into the other from the rear, a yieldingly mounted endcontact carried by the inner of said parts arranged for engagement withthe center contact of a socket, binding terminals also carried by saidpart, one of said binding terminals being connected with said endcontact, the other part having a corrugated contact, and cooperatingmeans carried by said parts for electrically connecting said corrugatedcontact with the other binding terminal when one of said parts isinsei-ted into the other.

6. A separable attachment plug comprising a shell and a body insertiblethereinto from the rear, binding terminals carried by said body, ayieldable end contact connected with one of said binding terminals andarranged to extend forward beyond said shell. saidshell having acorrugated contact, and coengaging means carried by said body and shellrespectively for connecting said corrugated contact with the other ofsaid binding terminals.

7. A separable attachment plug comprisin a shell and a body insertiblethereinto from the rear` binding terminals carried by said body, ayieldable end contact connected with one of said binding terminals andextending forward beyond said shell, said shell having a corrugatedcontact, co-engaging means carried by said body and shell respectivelyfor connecting said corrugated contact with the other of said bindingterminals, and means for locking said body and shell together.

8. A separable attachment plug comprising a body and a shell, said bodycarrying binding terminals and having an end contact connected with oneof said terminals and arranged to extend through said shell when theparts are put together, said shell including a corrugated contact, meanscarried by said shell and body for detachably securing said shell andbody together and making electrical connection between said corrugatedcontact and the other binding terminal.

9. In an attachment plug, a shell comprising a threaded contact, a bodyfor insertion into said shell from the rear, an end contact` carried bysaid body, said body .carrying also binding terminals, and means forlocking said body and shell together With said outei` contact and one ofsaid binding terminals in electrical connection when said body isinserted into said shell, said locking means being manually releasableto 'permit the parts to be readily separated.

10. An attachment plug comprising, in combination, a body, a yieldingend `contact carried thereby, binding terminals also carried by saidbody, a removable outer cont-act, and manually releasable interlockingmeans for securing said `outer contact on said body with sald outercontact in electrical connection with one of said binding terminals.

11. An attachment plug comprisin an insulating block, a current carryingracket secured to said block and a spring-controlled plunger passingthrough an arm of the bracket and adapted to engage a `center contact. s

12. An attachment plug comprising an insulating block having a recess, acurrent carrying bracket secured inV said recess, a plunger socketed inthe recess and engaging the bracket and a spring acting to retain theplunger in position to engage' a center contact.

13. An attachment plug comprising an insulating block, a currentcarryingbracket secured to said block, a plunger socketed in the block andhaving 'a reduced end passing through the bracket and leaving a shoulderand a spring surrounding the plunger and bearing against the shoulderand the bracket to retain the plunger in operative position.

In Witness whereof, I- have hereunto subscribed my name in the presenceof two wit- M.`L. FARRAR, C. L. HOPKINS.

